Concealed zip fastener

ABSTRACT

A concealed zip fastener is provided with a pair of stringer tapes carrying thereon rows of fastener elements, each of said tapes being provided on one surface with longitudinally extending alternate ridges and grooves. A selected one of these grooves is located close to or flush with the plane of the coupling head portion of the element and functions as an axis of fold about which the tape is folded on itself.

United States Patent [191 [111 3,922,760

Matsuda Dec. 2, 1975 CONCEALED ZIP FASTENER 3,708,836 1/1973 Frohlich 24/2051 c 3,714,683 2/1973 [75] inventor: Matsuda Nyuzen, Japan 3,762,002 10/1973 Frohlich 24/205.l6 c 73 AssigneeI Y hi Kogyo K K Tokyo Japan 3,820,202 6/1974 Takamatsu 24/205.1 C

[22] Filed: 1972 Primary Examiner-Bernard A. Gelak [21] Appl. No.: 312,292 Attorney, Agent, or FirmBucknam and Archer [30] Foreign Application Priority Data [57] ABSTRACT Dec 2L l 7] Japan 46 103885 A concealed zip fastener is provided with a pair of [52] U 8 Cl 24/205 1 0 24/205 16 C stringer tapes carrying thereon rows of fastener ele- [511 A448 i9/12 ments, each of said tapes being provided on one sur- [58] Field 24/205 1 C face with longitudinally extending alternate ridges and grooves. A selected one of these grooves is located [56] References Cited close to or flush with the plane of the coupling head portion of the element and functions as an axis of fold UNITED STATES PATENTS about which the tape is folded on itself. 3,484,906 12/1969 Yoshida 24/205.1 C 3,590,881 7/1971 Van Amburg 24/205.l C 4 Claims, 13 Drawing Figures Sheet 1 of 3 FIGJ FIG.2

Sheet 3 of 3 US. Patent Dec. 2, 1975 FIG.1O

FIG.9

1 l 16 16d 16C 16b 16a FIGJZ CONCEALED ZIP FASTENER BACKGROUND OF THE INVENTION Zip fasteners having two rows of interlocking fastener elements formed from a continuous filament or wire and secured to respective folded edges of opposed stringer tapes are well known, and such fasteners when closed by the slider mask the elements from external view, only leaving a linear seam in the junction of the opposed tapes.

The so-called concealed zip fasteners of known type are designed to maintain the effect of concealing or masking the fastener elements by folding the respective element-carrying edges of stringer tapes on themselves about the sewn seam which secures a rows of elements to the tape and which extends longitudinally of the tape and outermost of the elements or close to the coupling heads thereof. To obtain a maximum of the concealing effect, it is necessary to locate the sewn seam, which defines an axis of fold, as close to the coupling heads of the elements as possible. But, if the sewn seam is brought too close to the coupling heads, it will obstruct their coupling engagement with those on the mating tape. Therefore, the known concealed zip fasteners have suffered from the tendency that the coupling elements are exposed to sight when lateral forces are exerted tending to split the two tapes apart.

SUMMARY OF THE INVENTION Whereas, it is the primary object of the present invention to provide an improved concealed zip fastener which will eliminate the aforesaid difficulties of the prior-art fasteners.

It is a more specific object of the invention to provide an improved concealed zip fastener which is provided with a folded edge of the tape located as close to the coupling heads of the elements as required to maintain the desired concealing effect without obstructing the coupling operation of the fastener elements.

These and other objects and features of the invention will appear more clear from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings in which like reference characters refer to like or corresponding parts throughout the several views.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a transverse cross-sectional view of an element-carrying tape embodying the invention and shown in a disposition prior to folding of the tape;

FIG. 2 is a transverse cross-sectional view of the same shown as in folded disposition;

FIG. 3 is a transverse cross-sectional view of two opposed stringer tapes of the type shown in FIG. 2 and as in interengaged or coupled disposition;

FIG. 4 is a transverse cross section of an element-free tape employed in accordance with another embodiment of the invention;

FIG. 5 is a transverse cross-sectional view of the tape of FIG. 4 carrying a row of elements and shown as in folded disposition;

FIG. 6 is a transverse cross section of an element-free tape according to a further embodiment of the invention;

FIG. 7 is a transverse cross-sectional view of the tape of FIG. 6 carrying a row of elements and shown as in folded disposition;

FIG. 8 is a transverse cross-sectional view of a pair of stringers of the type shown in FIG. 7 and shown as interengaged;

FIG. 9 is a transverse cross section of an element-free tape according to still another embodiment of the invention;

FIG. 10 is a transverse cross-sectional view of the tape of FIG. 9 carrying a row of elements and shown as in folded disposition;

FIG. 11 is a transverse cross-sectional view of a pair of stringers of the type shown in FIG. 10 and shown as interengaged;

FIG. 12 schematically illustrates an example of the construction of a fastener tape employed in accordance with the invention, and

FIG. 13 is a transverse cross-sectional view of a modification according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and particularly to FIGS. 1 through 3 inclusive which illustrate a first embodiment of the invention, there is shown a concealed type zip fastener 10 which essentially comprises a stringer tape 11 and a row of fastener elements 12 mounted thereon. More specifically, the row of elements 12 in the form of a spring coil are secured by means of needle threads 13 to one longitudinal edge portion of the tape 11 and through the medium of a re inforcing cord 14 inserted in the element row in the usual manner. The stringer tape 11 which constitutes an important aspect of the invention is provided on one surface with alternate ridges 15 and grooves 16, while the other surface is rendered flat. A tape of this structure is preferrably formed by warp knitting, a typical example of which is shown in FIG. 12. This warp-knit ted tape is comprised of chain stitches 17 forming wales which correspond to the above ridges l5, tricot stitches 18 and weft threads 19 laid in coursewise to interconnect between the chain stitches 17, with grooves 16 formed warpwise between adjacent wales or ridges 15.

Each individual coupling element 12 is provided in the lower leg portion 12a with a recess 12b for receiving therein sewing or needle threads 13 in a manner such that the threads 13 do not present themselves above the surface of the element and are furthermore anchored firmly in place. The elements 12 are sewn with their upper leg portions borne against the flat surface of the tape 11 as shown in FIG. 1, in which instance the needle threads 13 on the tape side are embedded in the grooves 16. For purposes of illustration, there are provided two lines of stitching S and S for securing the elements 12 to the respective tapes 11. The first line of stitching S lies in the first or innermost groove 16a defined between the first ridge or wale 15a which constitutes a selvage of the tape 11 and the second ridge 15b. The second line of stitching S similarly lies in the second groove 16b defined between the second ridge 15b and the third ridge 150. In the case of the prior-art devices, the stitching S would be required to lie much closer to the coupling head 12d of the element 3 12 since it would define an axis of told about which to turn the tape over as previously stated.

In accordance with the invention, there isprovided a first axis of fold 20 which extends longitudinally of the tape 11 and about which the tape 11 is folded on itself over the element 12 is defined by a selected groove 160 formed between the third and fourth ridges or wales 15c and 15d, and not directly by the stitching S It will be appreciated that the first axis of fold 20 can be extended, as desired, closer to the coupling head 12d by a distance corresponding to the width of a selected ridge or wale 15c. To permit the tape 1 l to flex or bend outwardly exactly at the first axis of fold 20, it is important that the second groove 16b in particular be filled full with needle threads 13 so as to retain the third ridge 15c firmly in position against displacement.

The tape 11 is folded, as shown in FIG. 2, about the first axis of fold 20 and further about the second axis of fold 21 which is defined by a fourth groove 16d formed between the fourth and fifth ridges 15d and 152. The tape 11 thus folded substantially in the form of U presents a folded marginal edge portion 22 which projects outwardly into the coupling region 23 where the opposed rows of elements 12 are coupled together. It will be seen that with the fastener in closed position as shown in FIG. 3, the folded marginal edge portions 22 of the two mating tapes 11 abut against each other in intimate relation and form a junction 24 which is rendered resistant to the tendency of splitting apart by the provision of the third ridge 15c which is fixed in place by the needle thread S FIGS. 4 and illustrate a second preferred embodiment of the invention which is substantially identical in the inventive principles with the above-described first embodiment, with the exception that the third ridge or wale 150 is greater in width and height. The fastener according to this embodiment features the fact that the first axis of fold 10 is shifted outwardly closer to the coupling head 12d for a distance corresponding to the increased width of the ridge c, with the folded marginal edge portion 22 lying substantially flush with the plane of the coupling head 12d, whereby the opposed folds 22 are more intimately matched together to provide increased concealing effect. To obtain a larger dimension of the third ridge 15c as illustrated, the corresponding wale in the knit system of FIG. 12 may be for example formed with threads of increased denier or bundles of increased number of threads.

The third embodiment of the invention shown in FIGS. 6 through 8 inclusive is also similar in the inventive concept to the first embodiment except for the fourth ridge 15d which is greater in width and height than the rest of the ridges 15. This is intended to provide increased height of the folded marginal edge portion 22, viz. increased distance between the first and second axes of fold 20, 21. With the fastener 10 closed as shown in FIG. 8, the opposed folded portions 22 are brought coherently together as the rows of elements 12 are interlocked by a slider (not shown). The resulting junction 24 is greater in height as viewed in the drawings so that it becomes more resistanct to opening even under the influence of severe lateral forces tending to split apart the two stringer tapes. It will be understood that the features peculiar to the third embodiment may be achieved by enlarging the fourth ridge 15d in a manner similar to the second embodiment already described.

Reference to FIGS. 9 through 11 inclusive shows the fourth embodiment of this invention which incorporates the features noted of both the second and third embodiments. It will be seen that both the third and fourth ridges 15c, 15d are greater in width and height than the remaining ridges 15, with the result that the aspect of locating the first axis of fold 20 closer to the plane of the coupling head 12d and the aspect of increasing the distance between the first and second axes of fold 20, 21 are simultaneously achieved.

Having thus descirbed the invention, it will be understood that varb us changes, substitutions or modifications may be made in the precise form and construction herein above described and illustrated, without departing from the scope of the appended claims. As for an example, the fancy stitching of the needle thread S may be accommodated in the grooves 16 of the tape 11 as shown in FIG. 13.

What is claimed is:

1. A concealed zip fastener comprising a pair of opposed stringer tapes each carrying a corresponding row of fastener elements with coupling heads, each tape having on one side longitudinally extending alternate ridges and grooves, said row of fastener elements being secured to the tape along a longitudinal edge portion thereof by threads which run through and fill up certain grooves in said longitudinal edge portion, each tape being folded on itself about a fold axis defined by the groove which does not receive therein the threads and is positioned contiguously to that ridge which is one of the ridges fixedly placed on the fastener elements by the threads filing up the adjacent groove remote from the last-mentioned groove and is located in most closely intimate relation to the coupling heads of the fastener elements, the folded edge areas of said tapes being disposed in abutting contact when said rows of fastener elements are in coupled engagement.

2. The concealed zip fastener as defined in claim 1 wherein said stringer tape is of a warp knitted structure comprising a chain stitch forming said n'dge, a tricot stitch and a laid-in weft thread.

3. The concealed zip fastener as defined in claim 1 wherein said ridge is greater in width and height than the remaining ridges to allow the folded edge portion of each tape to be substantially flush with the coupling heads of the fastener elements.

4. The concealed zip fastener as defined in claim 1 wherein said ridge and another ridge adjoining said groove forming the fold axis are both greater in width and height than the remaining ridges for concealment of the fastener elements from external view. 

1. A concealed zip fastener comprising a pair of opposed stringer tapes each carrying a corresponding row of fastener elements with coupling heads, each tape having on one side longitudinally extending alternate ridges and grooves, said row of fastener elements being secured to the tape along a longitudinal edge portion thereof by threads which run through and fill up certain grooves in said longitudinal edge portion, each tape being folded on itself about a fold axis defined by the groove which does not receive therein the threads and is positioned contiguously to that ridge which is one of the ridges fixedly placed on the fastener elements by the threads filing up the adjacent groove remote from the last-mentioned groove and is located in most closely intimate relation to the coupling heads of the fastener elements, the folded edge areas of said tapes being disposed in abutting contact when said rows of fastener elements are in coupled engagement.
 2. The concealed zip fastener as defined in claim 1 wherein said stringer tape is of a warp knitted structure comprising a chain stitch forming said ridge, a tricot stitch and a laid-in weft thread.
 3. The concealed zip fastener as defined in claim 1 wherein said ridge is greater in width and height than the remaining ridges to allow the folded edge portion of each tape to be substantially flush with the coupling heads of the fastener elements.
 4. The concealed zip fastener as defined in claim 1 wherein said ridge and another ridge adjoining said groove forming the fold axis are both greater in width and height than the remaining ridges for concealment of the fastener elements from external view. 